Broken spark plug.
 

A guy I work with has a boat with a GM 4.3L I/O setup. He was going to change the spark plugs and I guess they rusted in and he managed to shear the whole end of the plug off – nothing but the threads are left in the head. The nut, the insulator, even the electrode came out.

Anything he can do short of pulling the heads off? I might think some PB Blaster, maybe some heat and an e-z out of some sort should get the remainder out, but I would be concerned with debris in the chamber.

Thoughts?

drill and tap while holding a vaccume nozzle close to it

I've never used these but a tech from Ford said they use them for the Triton spark plug problems. I think he said they also use heli coils if the threads aren't repairable. A little expensive from MAC, maybe find them in a different brand. Reverse Tap

I had the same thing happen on my brother's boat. I used a square tapered bolt extractor and a 3/8 impact gun on low. Worked like a champ.:nod:

neverseize ftw! before trying anything, get some pb on that baby. is it flush with the head?

Unless you get anti-sieze near the electrodes. Then it's FTMFL.

my guess its fixed already but i would take a mapp gas torch and heat it red hot than as was said hammer into the hole left by all coming out a squair stud remover and a 3/8s inpact and click it back and forth cant screw it up and more if head has to come off than it does anyway -- jz